Malocclusions: Common Problems with Bite and Teeth

If something seems a little "off" about your smile, you may have a malocclusion class I, II, or III. A malocclusion, or "bad bite," is the misalignment of teeth, which can cause a problem in the way your bite fits together. A malocclusion is often characterized by crooked or crowded teeth or an overlap in the jaw.

Occlusion refers to the perfect alignment of teeth, where the top teeth slightly overlap the bottom teeth and the cusps fit into the grooves of the teeth below. When any part of this structure is out of place, you have a malocclusion of teeth.

There are three different types of malocclusions, each divided into one of three malocclusion class systems: a Class I Malocclusion, Class II Malocclusion and Class III Malocclusion. Every malocclusion is divided into one of these classes to help your dentist properly diagnose and treat your problem.


Class I Malocclusion

Misaligned Teeth


Class I malocclusion involves crowding, spacing, or overlapping of the teeth. In this classification the upper jaw is in a normal relationship to the lower jaw; that is, neither jaw protrudes.

A Class I Malocclusion may also be signified by a slight overlap in teeth. This type of malocclusion is the most common.



Class II Malocclusion



Class II malocclusion occurs when the bottom jaw is in a more posterior (backward) position than normal. The top teeth appear to protrude out over the lower teeth. One example of this type of malocclusion is often referred to as "buck" teeth.

A Class II Malocclusion normally results from a larger top jaw or smaller bottom jaw than its counterpart.



Class III Malocclusion



Class III malocclusion occurs when the lower jaw is in a more anterior (forward) position than normal. The lower teeth protrude out beyond the upper teeth. This is often the most difficult type of malocclusion to correct.

A Class III Malocclusion is basically the opposite of a Class II Malocclusion, where the bottom jaw is larger than the top.



Crossbite Malocclusion



Ideally, your upper (maxillary) teeth should rest on the outside cusps of your bottom (mandibular) back teeth when closed, with the front top teeth slightly overlapping the lower jaw.

In a crossbite, the maxillary teeth touch the inside cusps of the mandibular teeth. A crossbite can affect just one tooth or your entire mouth and is often seen in the front or sides of the mouth.